Hypodermic needle



Feb. 3, 1970 D. KURTZ HYPODERMIC NEEDLE orginalFiled oct. e, 196e INVENFOR LEONARD D.. KURTZ ATTORNEYS United States Patent 3,492,992 HYPODERMIC NEEDLE Leonard D. Kurtz, Woodmere, N Y., assignor to Deknatel Inc., Queens Village, N.Y. Continuation of application Ser. No. 585,718, Oct. 6, 1966. This application Mar. 26, 1969, Ser. No. 810,853 Int. Cl. A61m 5/32; A61b 17/34 U.S. Cl. 12S-214.4 7 Claims ABSTRACT OF THE DISCLOSURE A hypodermic needle comprising a body portion and a cutting edge, the latter being located at the forward end of the needle adjacent the tip and extending from one side of the needle to the other across the maximum diameter of the needle. A channel extends longitudinally in the body portion for conveying fluid therealong, the channel opening onto the periphery of the needle only at points rearward of the cutting edge.

This application is a continuation of my previous application, Ser. No. 585,718, liled Oct. 6, 1966, now abandoned.

This invention relates to surgical instruments, and more particularly it relates to needles of the type generally referred to as hypodermic needles used to introduce fluid into, or remove fluid from the body.

Hypodermic needles are generally used for intracutaneous, subcutaneous, intramuscular or intravenous punctures. No matter what its useage, however, it is always important that the needle be as sharp as possible. Aside from the purpose of providing subjective comfort for the patient, sharpness is especially important in facilitating piercing of the veins or arteries. In some circumstances the blood vessel to be punctured will have a tendency to roll, that is, it will slide away from the needle as the operator attempts to puncture the vein or artery. The sharper the needle the less likely it will be that this rolling effect will occur.

I have previously found a way to maximize the sharpness of certain tissue cutting instruments other than hypodermic needles by employing a single Sharpe edge formed at the junction of two substantially flat surfaces as shown, for example, in my previous Patent Nos. 2,869,550, issued Jan. 20, 1959 and 3,094,123 issued June 18, 1963.

Hypodermic needles, however, serve a purpose essentially different from the tissue cutting instruments. Hypodermic needles are intended to pierce the skin and/or a selected area below the skin so that liquid can be delivered to or removed from the body area. To accomplish this purpose it is necessary to provide in the needle a channel for liquid flow and an opening from the channel at or near the tip of the needle. When the hypodermic needle is used in conjunction with a catheter tube, then the purpose of the needle is both to deliver the tube to the selected point in the body such as within a vein or artery, and to provide a means for detecting when the needle has entered the artery or vein, for example, so that the operator will know when to remove the needle from the inserted catheter tube. Although my previous tissue cutting instruments were designed to maximize tissue cutting, they were not designed to facilitate placement of a liquid opening near the tip of the tube and thus they do not easily lend themselves to use as a hypodermic needle.

Previous attempts to combine maximum sharpness with a liquid channel and a liquid opening near the tip of the needle employ a tapered tip construction. In these needles the tapered tip rst pierces the skin or other tissue below the skin after which the main portion of the tissue opening is formed by blunt dilation. However blunt dilation as a means for forming a tissue opening is gen- 3,492,992 Patented Feb. 3, 1970 erally undesirable since it is counter to one goal of all surgical instruments, namely to keep trauma to a minimum. Blunt dilation may tend to bruise or abrade the tissue through which it passes. Tissue damage and chemical release caused by the irritation and trauma increase pain, scar tissue formation, and a tendency of blood to clot. Moreover, non-sharp blunt dilation may lead to defects such as ragged or burred edges. Despite these disadvantages, however, no one has heretofore designed a hypodermic needle which achieves the main portion of the tissue opening, (that is, at least to the maximum diameter of the needle shaft) by cutting rather than by blunt dilation.

The purpose of the present invention is to provide an improved hypodermic needle in which the advantages of the full cutting action are combined with the necessary structure to provide uid oW.

According to a preferred embodiment of the present invention there is provided an hypodermic needle having a pointed tip, the point being located at a position on the circumference of the needle. A single cutting edge slants rearwardly from this point to a second point on the circumference of the needle opposite from the pointed tip, the single cutting edge being formed between these two points by the junction of two substantially plane surfaces. With this construction it is possible to form the main portion of the opening by cutting rather than by blunt dilation.

To provide for the flow of the liquid to or from the body a channel is provided in the needle having a channel opening located on the circumference of the needle at a point rearward of the cutting edge, that is, rearward of the second point of the cutting edge.

Positioning of the channel opening with respect to the cutting edge is important to the successful operation of the invention. When the opening is placed in the area of the cutting edge, the needle cuts a Wedge rather than a straight clean cut in the skin or other tissue being pierced. However, if the channel opening is positioned rearward of the cutting edge, the uid flow can be provided without reducing the efficiency of the tissue cutting operation.

To accomplish the purpose of the invention the channel and the opening therefrom can take various shapes and forms. In one embodiment of the invention the needle is used in conjunction with a catheter tube. A iluid flow channel may -be provided by forming in the surface of the needle a longitudinal groove which starts from a position rearward of the second point of the cutting edge and continues to the rear of the needle. The channel is formed by placing the catheter tube over the needle covering the groove so that the tube together with the groove forms a closed channel. The forward end of the catheter tube will terminate slightly behind the forward en-d of the channel to provide the channel opening. When the needle has entered the blood vessel a sufficient extent so that the channel opening has also entered the vessel, then either as a result of body pressure of syringe pressure blood will start immediately to ow through the channel. Consequently the operator will know exactly when the needle and the tube have entered the vessel. The needle can then be removed from the vessel leaving the tube positioned therein.

In an alternative embodiment the closed longitudinal channel may be provided entirely within the needle completely independent of a catheter tube. The channel opening could be a radial bore hole extending from the channel to the circumference of the needle at a point thereon rearward of the second point of the cutting edge.

Thus it is an object of this invention to provide an improved needle of the type referred to for injecting lluids into, and withdrawing fluids from the body.

It is another object of this invention to provide a needle of the type referred to which combines in a single instrument maximum sharpness together with the structure for providing liquid flow to and from the body.

It is a further object of this invention to provide a hypodermic needle which achieves the main portion of the tissue opening solely by cutting, exclusive of blunt dilation.

Other objects and the attendant advantages of the present invention will 'become apparent from the detailed description of the preferred embodiments of the invention to follow, together with the accompanying drawings in which:

FIGURE 1 is a side elevational view of a preferred embodiment of the invention.

FIGURE 2 is an en-d elevational View taken along line 2 2 of FIGURE 1.

FIGURES 3, 4, and 5 are sectional views taken along lines 3 3, 4 4 and 5 5 of FIGURE 1 respectively.

FIGURE 6 is a side elevational view of a second ernbodiment of the invention.

FIGURE 7 is a sectional view taken along line 7 7 of FIGURE 6r.

FIGURES 1-5 show a hypodermic needle 10 according to the present invention.

At the tip of the needle there is provided a structure for forming the main portion of the tissue opening solely by cutting. -From a pointed tip 11, a cutting edge 12 extends rearwardly to a second point 15. Plane surfaces 13 and 14 meet between points 11 and 15 to form the cutting edge 12, and these plane surfaces extend rearwardly to edges 19 and 20 respectively. Referring to FIGURES l and 2 it can be seen that this cutting edge 12 extends completely across a diameter of the needle from one side thereof to the other. This cutting edge 12 will provide the tissue opening up to the maximum diameter of the needle by a cutting action rather than by blunt dilation. The remainder of the opening, that is, the rounding out of the tissue opening, may be accomplished by blunt dilation by the portions of the needle behind the cutting edge 12.

Behind the cutting end of the needle is the body portion 16. A longitudinal groove 17 shown in FIGURES l, 4 and 5, extends along the circumference of the body 16 to a forward end 18, for conveying a liquid to or from the area surrounding the cutting end of the needle. The groove 17, in cooperation with a catheter tube 21 forms an enclosed channel through which the liquid flows. The forward end of catheter tube 21 terminates short of the forward end 18 of the groove 17 thereby providing an opening from the channel to the area around the cutting end of the needle. As noted earlier, this channel opening must be located rearward of the' cutting edge, that is, rearward of the point 15. When the needle is used to inject or withdraw uid to or from a blood vessel, the blood in the vessel will start to flow into groove 17 as soon as the needle channel opening at groove end 18 has entered the vessel thereby providing a means for detecting when the needle has entered the vessel.

In order to enhance the flow of fluid into and out of the channel opening, a circumferential groove 24 may be provided, as shown in FIGURES 1 and 4. As shown in FIGURE 1 the end 18 of the groove 17 is rearward of the edges 19 and 20 of the plane surfaces 1.3V and 14. However the end 18 may in fact ,be located forward of the rearwardmost point of edges 19- and 20 so long as end 18 and groove 24 are rearward of the point 15. If the groove end 18 is located forward of the rearwardmost part of edge 20, then the circumferential groove 24 would extend only from the groove 17 to the plane Surfaces 13 and 14.

When the needle is to be employed with a catheter tube the metallic section of the needle behind the point may be decreased in diameter as shown in FIGURES l-5 so that the catheter plus the decreased diameter would be equal to the needle point diameter which precedes it,

making for a smooth passage of a catheter into the blood vessel. If the diameter of the needle is decreased in this manner, it will probably be desirable to make the junction of the catheter and the needle at some slope as shown at 30 in FIGURE 1 so that the needle could be withdrawn. Also the forward edge of the catheter should be sloped as shown at 31 in FIGURE 1 to allow tissue to slide over it more freely.

Referring now to FIGURES 6 and 7 there is shown an alternative embodiment 10 of the invention. Where this embodiment is similar to that shown in FIGURES l-S like numerals have been employed or the numerals have been deleted. The embodiment shown in FIGURES 6 and 7 may be employed independent of a catheter tube. Here the groove is provided as shown at 22 internally within the body of the needle. A radial bore hole 23 extends from the longitudinal groove 22 to the surface at the opening 25.

As a matter of choice, the opening 25 is shown in FIG- URE 6 to be forward of the rearwardmost portion of edges 19 and 20 and the circumferential groove 24 has been omitted. Of course this construction is also possible in the embodiment of FIGURES 1-5. Also, it is of course possible to extend a circumferential groove from the opening 25 toward the edges 19 and 20 thereby opening onto the plane surfaces 13 and 14.

Thus, there has been provided an improved needle of the type referred to combining both the necessary structure for fluid flow to and from the body and a cutting portion having maximum sharpness.

While the invention has been described in considerable detail with respect to preferred embodiments thereof, it should be apparent that numerous variations and modiications may be employed without departing from the spirit and scope of the invention as set forth in the appended claims wherein:

1. An instrument for conveying liquid to or from a body comprising an elongated needle having a longitudinal axis, said needle having a body portion and a cutting edge at the forward end of the needle and formed by the intersection of two planar surfaces, said cutting edge extending from a rst point on one side of the needle rearwardly to a second point on the other side of the needle and passing through the said longitudinal axis of the needle, the perpendicular distance between parallel longitudinal lines passing through the said first and second points being substantially equal to the maximum crosssectional dimension of the needle, a channel extending longitudinally and formed at least partially within said body portion of the needle, for conveying uid therealong, said channel permanently opening onto the periphery of the needle only at points rearward of said second point of said cutting edge, whereby as the needle is passed through a tissue and into a liquid containing area, the said cutting edge causes dilation of the tissue by a cutting action up to the said maximum cross-sectional dimension of the needle, and whereby after entry of the needle cutting edge into the body, the liquid therein passes into said opening and through said channel to give an indication that the cutting edge has passed the said tissue, and entered the said area.

2. An instrument according to claim 1, wherein said channel comprises a groove extending along the periphery of the body portion of the needle, and including a tubular sheath surrounding the said body portion rearward of the forwardmost end of the groove to form, with the groove, the said channel, wherein the said forwardmost end of the groove comprises the said opening onto the periphery of the needle.

3. An instrument according to claim 2 wherein the needle is generally cylindrical and the diameter of the portion of the needle enclosed within the tubular sheath is reduced with respect to the maximum diameter of the needle between the forward end of the sheath and the cutting edge, and wherein the maximum diameter of the sheath is substantially equal to the said maximum diameter of the needle.

4. An instrument according to claim 3, wherein the transition portion of the needle from the maximum diameter to the reduced diameter comprises a smooth curve, and wherein the forward end of the tubular sheath is curved inwardly and located at the said transition portion of the needle.

S. An instrument according to claim 2 including a circumferential groove on the needle at said opening.

6. An instrument according to claim 1, wherein the said channel is formed totally within the needle, and wherein said opening comprises a radially extending passage from the channel to the lateral periphery of the needle.

7. An instrument according to claim 6, including a circumferential groove on the needle at the said opening.

References Cited UNITED STATES PATENTS Hanson 12S-221 Owings 128-221 Koehn 12S-214.4

Palmer 12S-221 De Luca 12S-221 Everett 12S-339 Kurtz 12S-339 Kurtz 12S-339 Hirsch 12S-214.4

U.S. Cl. X.R. 

